[llvm-commits] [llvm] r120841 - /llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp

[Jakob Stoklund Olesen]

On Dec 3, 2010, at 1:52 PM, Evan Cheng wrote:

> When does this happen? Would this affect codegen in the presence of debug info? Or are these virtual registers only used to track debug info liveness?

I think this is just a badly named variable. It is not an llvm::VirtRegMap instance, it maps virtual registers to the debug variables that use it.

It won't affect codegen, and no extra virtual registers are created.

I wil rename it to virtRegToUserValue.

> 
> Evan
> 
> On Dec 3, 2010, at 1:47 PM, Jakob Stoklund Olesen wrote:
> 
>> Author: stoklund
>> Date: Fri Dec  3 15:47:08 2010
>> New Revision: 120841
>> 
>> URL: http://llvm.org/viewvc/llvm-project?rev=120841&view=rev
>> Log:
>> Also update virtRegMap when renaming virtual registers.
>> 
>> Modified:
>>   llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp
>> 
>> Modified: llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp?rev=120841&r1=120840&r2=120841&view=diff
>> ==============================================================================
>> --- llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp (original)
>> +++ llvm/trunk/lib/CodeGen/LiveDebugVariables.cpp Fri Dec  3 15:47:08 2010
>> @@ -583,8 +583,18 @@
>> 
>> void LDVImpl::
>> renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx) {
>> -  for (UserValue *UV = lookupVirtReg(OldReg); UV; UV = UV->getNext())
>> +  UserValue *UV = lookupVirtReg(OldReg);
>> +  if (!UV)
>> +    return;
>> +
>> +  if (TargetRegisterInfo::isVirtualRegister(NewReg))
>> +    mapVirtReg(NewReg, UV);
>> +  virtRegMap.erase(OldReg);
>> +
>> +  do {
>>    UV->renameRegister(OldReg, NewReg, SubIdx, TRI);
>> +    UV = UV->getNext();
>> +  } while (UV);
>> }
>> 
>> void LiveDebugVariables::
>> 
>> 
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>